Turbocompressor

ABSTRACT

A turbocompressor that is suitable for conveying a multi-phase mixture, comprising a housing having a guiding device and comprising a shaft having at least one impeller, wherein the turbocompressor has an expansion chamber through which the multi-phase mixture can flow on the suction side and a contraction chamber arranged downstream is provided.

FIELD OF TECHNOLOGY

The invention relates to a turbocompressor which is suitable for conveying a multi-phase mixture, comprising a housing having a guiding device, and a shaft having at least one impeller.

BACKGROUND

Turbocompressors are used to convey a fluid by transmitting kinetic energy in the form of a rotational impetus. A conveyed gas is compressed here in a compressor. A typical application is to convey natural gas, but the problem may occur here that the conveyed natural gas has a gas phase and a liquid phase. Customary turbocompressors are, however, not suitable for conveying liquid droplets since these can bring about erosion in the housing of the turbocompressor or on impellers.

In order to avoid this problem it has already been proposed to integrate into the turbocompressor a separator which is based on centrifugal precipitation. However, the structural complexity involved in an additional separator is comparatively high. Furthermore, it has been found that even when a separator is used, what are referred to as slugs (plugs of liquid) break through briefly so that the turbocompressor has to at least briefly convey a mixture of gas and liquid. The conveyed liquid can comprise both water and oil.

DE 10 2005 003 037 A1 discloses a precipitator device for precipitating liquid particles from a gaseous medium. DE 41 19 794 A1 discloses a device for precipitating oil components contained in the intake air of an internal combustion engine. A device for precipitating particles from an exhaust gas stream is disclosed in DE 195 15 352 A1.

The invention is therefore based on the object of specifying a turbocompressor which is suitable for conveying liquid droplets contained in a gas.

SUMMARY

In order to achieve this object, in a turbocompressor of the type mentioned at the beginning there is provision according to the invention that said turbocompressor has, on the suction side, an expansion chamber through which the multi-phase mixture can flow and a contraction chamber which is arranged downstream.

The invention is based on the realization that by means of the expansion chamber arranged in the intake region and the associated contraction chamber it is possible to bring about homogenization of the multi-phase mixture, during which fine droplets of the liquid phase form which can be conveyed by the turbocompressor. In the expansion chamber a sudden expansion takes place and when the downstream contraction chamber is passed the fine droplets form which permit a conveying process. In this way, the permissible portion of the liquid phase can be increased.

In the case of the turbocompressor according to the invention it is preferred that the expansion chamber and the contraction chamber are arranged upstream of an intake connector of the turbocompressor. The two chambers can therefore be embodied as a separate device which is arranged or mounted on the suction side of a turbocompressor. However, it can alternatively be provided that the expansion chamber and the contraction chamber are arranged in an intake connector of the turbocompressor. In this refinement, the two chambers are integrated into the turbocompressor, specifically into the intake connector of the turbocompressor, and this results in a particularly compact design. A further improvement of the turbocompressor according to the invention can be achieved if the expansion chamber has a section which increases in a conical shape in the direction of flow. This geometric refinement brings about a reduction in friction losses. In a similar way it is possible to provide in the case of the turbocompressor according to the invention that the contraction chamber has a section which tapers in a conical shape in the direction of flow. This measure also reduces flow losses. In particular, the contraction chamber can be embodied as a Venturi nozzle in which an increase in pressure takes place by reducing the volume.

BRIEF DESCRIPTION

The invention will be explained below by means of exemplary embodiments and with reference to the drawings.

The drawings are schematic illustrations, and in the drawings:

FIG. 1 shows a first exemplary embodiment of a turbocompressor according to the invention; and

FIG. 2 shows a second exemplary embodiment of a turbocompressor according to the invention.

DETAILED DESCRIPTION

The turbocompressor 1 shown in FIG. 1 comprises a schematically illustrated housing 2 which has a guiding device 3 as well as a shaft 4 having an impeller 5. The shaft 4 has a plurality of impellers which are arranged axially one behind the other, and for reasons of clarity merely one impeller 5 is shown.

If multi-phase mixtures are conveyed with the turbocompressor 1, which multi-phase mixtures contain both a gas phase and a liquid phase, it is found that despite a separator which is connected upstream, liquid droplets are sucked in which have a disadvantageous effect on components of the turbocompressor 1. For this reason, the turbocompressor 1 has, on the suction side 6, an expansion chamber 7 which has a larger cross section than a pipeline 8 which opens into it. If the conveyed medium flows into the expansion chamber 7 via the pipeline 8, expansion takes place. The expansion chamber 7 is adjoined by a contraction chamber 9 which has a smaller cross section than the expansion chamber 7. Accordingly, the fluid flowing in the direction of the arrow 10 is compressed again in the contraction chamber 9.

Fine droplets are formed as a result of the expansion which suddenly occurs in the expansion chamber 7 and the sudden restriction of the flow which occurs in the contraction chamber 9 which is arranged downstream. In this way, if appropriate, non-homogeneously distributed liquid droplets which are contained in the multi-phase mixture are homogenized, that is to say the size of the droplets is reduced and uniformly distributed droplets are formed. The droplets which are distributed uniformly in the gas-liquid mixture can readily pass through the compressor without erosion occurring. Accordingly, a relatively high portion of liquid can be permitted in a multi-phase mixture which is essentially present in a gaseous form, which is necessary, inter alia, for the use under water. An in-line separator can be arranged upstream of the turbocompressor 1. Trials have shown that by combining the expansion chamber with the contraction chamber it is possible to achieve a portion of droplets of at least 70% of the liquid phase.

FIG. 2 shows a second exemplary embodiment of a turbocompressor 11 which is constructed in a similar way to the turbocompressor 1 shown in FIG. 1. Therefore, the same reference symbols as in the first exemplary embodiment are used for corresponding components.

In accordance with the first exemplary embodiment, the turbocompressor 11 comprises a housing 2 having a guiding device 3 and a shaft 4 having at least one impeller 5. In the case of the turbocompressor 11, the expansion chamber 12 is embodied in such a way that it has a section which increases in a conical shape in the direction of flow, which is illustrated by the arrow 10. In this refinement of the expansion chamber 12, the flow losses are smaller compared to the expansion chamber 7 of the first exemplary embodiment. In a similar way, the contraction chamber 13, which is arranged downstream of the expansion chamber 12, is embodied in such a way that it has a section which tapers in a conical shape in the direction of flow. A sudden expansion, followed by a sudden contraction of the flowing medium is brought about by the combination of the expansion chamber 12 with the contraction chamber 13 arranged downstream, as a result of which the desired homogeneous production and distribution of liquid droplets contained in the gas phase occur. Accordingly, the fluid which flows in on the suction side 6 has finely distributed droplets which can readily pass through the compressor stage of the turbocompressor 11. 

1-6. (canceled)
 7. A turbocompressor that is suitable for conveying a multi-phase mixture, comprising: a housing having a guiding device, and a shaft with at least one impeller, wherein the turbocompressor has, on a suction side, an expansion chamber through which the multi-phase mixture can flow, the expansion chamber having a larger cross section than a pipeline which opens into the expansion chamber, and a contraction chamber that is arranged downstream, the contraction chamber having a smaller cross section than the expansion chamber to homogenize non-homogenously distributed liquid droplets contained in the multi-phase mixture and to form uniformly distributed droplets, further wherein the contraction chamber follows the expansion chamber in an accompanying fashion.
 8. The turbocompressor as claimed in claim 7, wherein the expansion chamber and the contraction chamber are arranged upstream of an intake connector of the turbocompressor.
 9. The turbocompressor as claimed in claim 7, wherein the expansion chamber and the contraction chamber are arranged in an intake connector of the turbocompressor.
 10. The turbocompressor as claimed in claim 7, wherein the expansion chamber has a section which increases in a conical shape in a direction of flow.
 11. The turbocompressor as claimed in claim 7, wherein the contraction chamber has a section which tapers in a conical shape in a direction of flow.
 12. The turbocompressor as claimed in claim 7, wherein the contraction chamber is a Venturi nozzle. 